Filter bodies may contain in a variety of configurations including a sieve or mats of fibres laid one over the other. The filter body removes particles from carrier fluid which are too large to pass through the apertures in the filter body. Smaller particles can be removed from the carrier fluid if some mechanism is provided for restraining them other than by physical obstruction. The present invention provides this mechanism for particles of protinaceous material.
It has been proposed to coat filter bodies with collagen, or to treat them by spark erosion, to provide a protein attracting surface, but these processes are expensive.